Forest, trees – you know the drill

One of the reasons malware gets past corporate defences is that a single HTTP request can look perfectly innocent. However, according to research to be presented at a security conference next week, those requests reveal themselves if the defender takes a “big picture” view.

According to research to be presented at the Internet Society's Network and Distributed System Symposium, at a very large scale, the HTTP requests issued by users who make the mistake of clicking on a malware link become easy to identify – even without having to analyse the content of the HTTP content downloaded.

Led by Luca Invernizzi at UC Santa Barbera, the research was designed to avoid the pitfalls of current protection systems. “Drive-by exploits use the web to download malware binaries. Finally, Nazca does not perform any analysis of the content of web downloads, except for extracting their MIME type. That is, we do not apply any signatures to the network payload, do not look at features of the downloaded programs, and do not consider the reputation of the programs’ sources,” the paper states.

Instead, their system, dubbed Nazca, watches Web traffic between hosts on one side of the network, and the Internet, looking for connections associated with malware downloads.